Examine source code of Em Dash Counter

{
  "name": "Em Dash Counter",
  "description": "Small badge to count the number of em dashes on a webpage",
  "version": "1.1",
  "manifest_version": 3,
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "action": {},
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "em-dash-counter@em-dash-counter",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}